The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 23, 2001
Filed:
Mar. 08, 2000
Steven L. Garrett, State College, PA (US);
Robert M. Keolian, State College, PA (US);
Robert W. Smith, State College, PA (US);
The Penn State Research Foundation, University Park, PA (US);
Abstract
A thermoacoustic driver incorporates a linear electrodynamic motor having electrical terminals and a moving part, a driver suspension housing, a piston, and a stiffness-enhancing device for raising the mechanical resonance frequency of the electrodynamic motor without reducing the piston stroke. The stiffness enhancement is accomplished by the use of specially optimized suspension spring structures and/or by attaching one or more electrical inductors to the electrical terminals of the driver. The stiffness enhancement using mechanical springs incorporates one or more starfish structures extending between the driver suspension housing and the piston and rigidly clamped to both. The starfish structures comprise radially extending legs, which are leaf springs or beams of varying width. The shape of the beams and the shape of the overall spring structure are optimized to enhance flexural or torsional stiffness and relieve arc tension within the constraints of cost-effectiveness. In one version, two modified triangular (trapezoidal) cantilever beams are connected through a straight middle section and form a bow-tie shaped beam.